refactor: unify evalClanService with evalService

lib/modules/inventory/distributed-service/evalService.nix

@@ -0,0 +1,30 @@
+/*
+  Example usage:
+
+  ```nix
+  evalService = import /this/file.nix { inherit lib clanLib; };
+  result = evalService { modules = []; prefix = []; };
+
+  => result.config
+  => result.options
+  ```
+*/
+{ lib, clanLib }:
+# <lambda evalService>
+{ modules, prefix }:
+lib.evalModules {
+  class = "clan.service";
+  specialArgs._ctx = prefix;
+  modules =
+    [
+      # Base module
+      ./service-module.nix
+      # Feature modules
+      (lib.modules.importApply ./api-feature.nix {
+        inherit clanLib prefix;
+      })
+    ]
+    ++
+    # Modules of caller
+    modules;
+}